Immunodominant sites of HTLV-I envelope protein

ABSTRACT

The invention relates to peptides representing CTL epitopes from the HTLV-I envelope protein. The invention further relates to compositions, comprising the peptides, for priming a T-cell response in a subject. Furthermore, methods for priming a T-cell response by administration of the compositions to a subject and methods for evaluating the T-cell function of a patient are described.

This application is a continuation application of application Ser. No.08/243,118, filed on May 16, 1994, now abandoned which in turn is acontinuation application of Ser. No. 07/401,411, filed Sep. 1, 1989 andnow abandoned. The entire contents of each of these applications ishereby incorporated in entirety by reference.

BRIEF DESCRIPTION OF THE INVENTION

HTLV-I (Human T-cell lymphotropic virus type I) is the retroviruscausally related to adult T-cell leukemia/lymphoma and also associatedwith a neurological disorder, tropical spastic paraparesis orHTLV-I-associated myelopathy. The development of these two differentdiseases among HTLV-I infected individuals may depend in part ondifferences in their T-cell immunity associated with a difference of HLAphenotype. Peptides corresponding to 17 sites in the HTLV-I envelopeprotein were tested for their antigenicity for lymph node cells fromB10.BR, B10.D2, B10.A(5R), and B10.HTT congenic mice, representing fourindependent MHC haplotypes, immunized with the native envelope protein.Ten of the 17 tested sites were predicted to be amphipathic α-helicalsites and all of them were found to be antigenic for at least one of thefour MHC congenic strains of mice. Three of the 17 sites wereamphipathic 3₁₀ -helical sites and four sites were predicted to benon-helical sites: none of the 3₁₀ -helical sites were antigenic andonly one of four non-predicted sites was found to be immunodominant.Furthermore, three potent immunodominant peptides, V1E1 (342-363),V1E8/SP4a (191-209), and V1E10 (141-156) were also shown to beimmunogenic; i.e., these peptides could be used to immunize mice toelicit proliferative responses of lymph node cells to the native HTLV-Ienvelope protein. Furthermore, these three peptides were able to primeanimals for an enhanced antibody response to the native protein. Becausethis priming followed the same Ir gene control as the proliferativeresponse, it probably reflects the ability of these peptides to primehelper T cells. The localization of immunodominant sites in HTLV-Ienvelope protein in mice may be useful for finding antigenic andimmunogenic sites in humans, for developing a peptide vaccine for thevirus, and possibly for aiding in prognosis for the development ofdifferent disease manifestations of HTLV-I infection.

BACKGROUND OF THE INVENTION

The human T-cell lymphotropic virus type 1 (HTLV-I) was the firstretrovirus shown to be causally related to a specific human malignancy,adult T-cell leukemia/lymphoma (ATLL) (Poiesz, et. al. Proc. Natl. Acad.Sci. U.S.A.77.7415-7419., Yoshida, M.,I. Miyoshi, and Y. Hinuma, et. al.Proc. Natl. Acad. Sci. USA79:2031-2035). Recently it was found that thesame virus was also associated with a chronic myelopathy in the tropicsand in southwestern Japan, HTLV-I-associated tropical spasticparaparesis (HTLV-I/TSP) (Johnson, et. al. Ann. Neurol 21:113-116.,Gessain, et. al. Lancet 2:407-410., Rodgers-Johnson et. al. Lancet2:1247-1248., Vernant, et. al. Ann.Neurol 21:123-130.) orHTLV-I-associated myelopathy (HAM) (Osame, et. al. Lancet 1:1031-1032.)The development of these two different diseases in HTLV-I infectedindividuals may depend in part on differences in the nature of patientT-cell responses to HTLV-I because there is some indication of an HLAphenotype-association with the risk of ATLL and TSP/HAM among HTLV-Iseropositive individuals, (Usuku et. al. Ann. Neurol 23:S143-S150. ThisHLA association of neurologic manifestations of HTLV-I infection can becorrelated with a difference in lymphocyte proliferative response to thevirus, namely, a high response in TSP/HAM and low response in ATLL. Forthese reasons, it was important to identify epitopes of HTLV-Irecognized by T cells, in order to begin to test the hypothesis thatT-cell responses to different HTLV-I epitopes might result in eitherprotective immunity or autoimmune disease. Because of the difficulty oftesting a large number of potential epitopes in patients, we have chosento first identify potent T-cell epitopes in mice. Experience frominfluenza (Lamb, et. al. Nature 300:66-69., Hurwitz J. Immunol133:3371-3377,) HIV, (Cease et. al. Proc. Nate. Acad. Sci. USA84:4249-4253., Berzofsky et. al. Nature 334:706-708) and malaria (Goodet. al. Science 235:1059-1062., Good et. al. Procl Natl. Acad. Sci. USA85:1199-1203., Dontfraid et. al Mol. Biol. Med., Sinigaglia et. alNature 336:778-780) indicate a good correlation between epitopesrecognized by murine T cells and those recognized by human T cells.

DeLisi and Berzofsky (Delisi el. al. Proc. Natl. Acad. Sci. U.S.A.82:7048-7052) analysed the sequences of immunodominant sites of proteinantigens and found that most of the T-cell epitopes corresponded toregions that could fold as amphipathic helices. An improved computeralgorithm "AMPHI" was developed for the prediction of amphipathichelical structures in proteins (Margalit el. al. J. Immunol.138:2213-2229) and applied to the prediction of immunodominant helperT-cell sites in the HIV-1 envelope protein (Cease et. al.Proc.Natl.Acad. Sci. USA 84:4249-4253) and Plasmodium falciparum malariacircumsporozoite protein (Good el. al. Science 235:1059-1062., Good el.at. Proc. Natl. Acad. Sci. USA 85:1199-1203).

FIGURE LEGENDS

FIG. 1. Location and predicted conformation of synthetic peptides. Row Ashows the predicted amphipathic α-helical sites (solid bars ) and 3₁₀-helicaI sites (hatched bars). Based on the prediction, the peptides(V1E1-10) in line B were synthesized. The line C shows the location ofanother series of peptides (SP1-11)[24]; these sites are relativelyhydrophilic sites in the HTLV1 envelope protein. V1E8 and SP5 arecompletely included in SP4a and V1E9, respectively. Also, V1E7 and SP2,V1E4 and SP8, and V1E5 and SP10 partially overlap.

FIGS. 2A, 2B. Proliferative responses of native envelope protein-immunelymph node cells of B10.BR (A) and B10.A(5R) (B) mice to the immunogenand the synthetic peptides recognized by at least one of the testedstrains: V1E1 (▴), V1E2 (Δ), and VIE9 (□) for B10.BR, V1E8 () forB10.BR and B10.A(5R), and V1E10 (◯) for B10.A(5R) ("NP" experimentsdescribed in the text). Responses to PPD (▪) are also shown. HTLV1envelope protein-immune lymph node cells (4×10⁵ /well) were culturedwith various concentration of peptides for 5 days and the cultures werepulsed with 1 μCi of [³ H]-TdR for the last 16 h. Results are expressedas Δ geometric mean (cpm)×SEM. Control cultures without antigen gave2,548 cpm for B10.BR and 3,394 cpm for B10.A(5R).

FIGS. 3A through 3I. Responses of peptide-immune lymph node cells to thenative envelope protein ("PN" experiments described in the text) andpotent antigenic peptides. The left column shows the response of B10.BRlymph node cells immunized with peptides, V1E1 (A-C), V1E8 (D-F), andV1E10 (G-I), to native envelope protein (), V1E1 (▴), V1E8 (◯), V1E10(□) and PPD (▪). The middle and right vertical columns show theresponses of B10.D2 and B10.A(5R)mice, respectively. The data are shownas Δ geometric mean (cpm)×SEM. The no-antigen backgrounds were: B10.BR,11,743 cpm (V1E1), 5,280 cpm (V1E8), and 7,855 cpm (V1E10); B10.D2,9,437 cpm (V1E1), 3,121 cpm (V1E8), and 7,340cpm (V1E10); B10.A(5R),10,205 cpm (V1E1), 2956 cpm (V1E8), and 5,395 cpm (V1E10).

FIGS. 4A-4B. Ability of peptide preimmunization to enhance the antibodyresponse to native HTLV-I envelope glycoprotein. Five mice perexperimental group of each strain (B10.BR, A, and B10.A(5R), B) werepreimmunized i.p. with 10 nmoles of the indicated peptide in CFA, or PBSin CFA as a control, and 15 days later were boosted with 5.6 μg ofaffinity purified envelope protein in IFA. Bleeds were taken before thepeptide immunization and at the indicated times after the immunizationwith whole protein. Antibodies from individual animals were assayed induplicate for binding to whole affinity-purified envelope protein asdescribed in Materials and Methods. The geometric mean titer for eachgroup of five animals is plotted, with geometric standard error of themean.

MATERIALS AND METHODS

Mice. B10.D2 (I-A^(d), I-E^(d)),B10.BR (I-A^(k), I-E^(k)) and B10.A (5R)I-A^(b), I-E.sub.β^(b) E.sub.α^(k)) mice were obtained from the JacksonLaboratory (Bar Harbor, Me.). B10.S (9R) (I-A^(s), I-E.sub.β^(s)E.sub.α^(k)) and B10.HTT (I-A^(s), I-E.sub.β^(s) E.sub.α^(k)) mice werebred in our facility.

Purified viral protein. The HTLV-I envelope protein was obtained from aTriton X-100 lysate of HTLV-I-infected HUT-102 cells using an affinitycolumn made with purified IgG from an HTLV-I seropositive subject asdescribed [19].

Sequence analysis of HTLV-I envelope protein and prediction of T-cellantigenic sites. Polypeptide segments segments with helicalamphipathicity, that is, segments which, if helical, would havehydrophilic residues on one face and hydrophobic residues on theopposite face, are predicted to be frequently immunodominant sites inprotein antigens seen by T-helper cells and cytotoxic T-cells[17,18,20-22]. The helical amphipathicity of the HTLV-I envelope proteinwas analysed with a computer algorithm, AMPHI, and 15 potential siteswere identified as shown in FIG. 1. Hydrophilic regions of HTLV-I gp46and p21 were identified by the method of Kyte and Doolittle [23].

Peptide synthesis. Two series of HTLV-I envelope peptides were preparedindependently under two different strategies (Table 1). In one series,eight peptides based on the prediction of helical amphipathicity (V1E1,V1E2, V1E3, V1E4, V1E5, V1E6, V1E7, V1E8, and V1E9) and onenon-predicted control peptide (V1E10) were synthesized. For the otherseries, 10 peptides (SP1-6,SP8-11) were synthesized on a Dupont 2100solid phase peptide synthesizer [24] based upon the high hydrophilicityof sequence without analysing their conformation, originally in order tosearch for B-cell epitopes [24]. The V1E series of peptides weresynthesized on an Applied Biosystem 430 A peptide synthesizer by usingthe solid phase peptide synthesis method [25,26] and cleaved from theresin by hydrogen fluoride (HF). The low/high HF method [26] wasemployed for peptide V1E9 to remove the formyl protecting group fromtryptophan and the standard high HF method was used for the otherpeptides. The peptides were purified by gel filtration on a Biogel P4column in 9% formic acid. In the case of the peptides V1E9 and V1E10,for which we detected a spontaneous stimulatory effect even afterBio-gel purification, further purification was performed by preparativereverse phase HPLC.

Immune lymph node cell proliferation assay. Mice were immunized witheither 0.1 nmole of purified envelope protein or 3 nmol of peptide in 50μl of complete Freund's adjuvant (Difco) subcutaneously at the base ofthe tail. Eight days later, a single cell suspension of the draininglymph nodes was prepared and the cells were plated in quadriplicate at 3or 4×10⁵ /0.2 ml in flat-bottomed Costar 96-well plates in completemedium with or without antigens as described [27]. The cultures werepulsed with 1 μCi of [³ H] TdR (6.7 Ci/mmol; New England Nuclear,Boston, Mass.) for the last 16 hr of a 5-day culture and incorporated [³H] was estimated by β-emission spectroscopy.

Immunization for antibody responses. Mice were prebled and thenimmunized i.p. with 10 nmoles of a given peptide in CFA or with PBS inCFA, bled 14 days later, and boosted on day 15 with 5.6 μg of affinitypurified envelope protein in IFA. Bleeds were taken at weekly intervalsthereafter.

Antibody solid-phase radioimmunoassay. Antibody to whole HTLV-I envelopeprotein was measured by solid-phase radiobinding assay as described[24]. Briefly, Immulon 2 microtiter plates (Dynatech) were coated withaffinity purified protein, prepared as described above, in sodiumcarbonate buffer, pH 9.6 overnight at 4° C., then washed, blocked with5% nonfat dry milk in coating buffer for 2 hr at 4° C., and washed withPBS containing 0.5% Tween 20, 3% nonfat dry milk, and 0.1% azide. Serafrom individual mice were serially diluted and each dilution wasincubated in duplicate wells coated with antigen for 1 h at 23° C. Wellswere washed three times and developed with a 45-min incubation with 50μl of a 1/200 dilution of rabbit anti-mouse IgG (BCA/Cappel Products,West Chester, Pa.), followed by a wash and a 30-min incubation with 10⁵cpm/well of ¹²⁵ I protein A. Each plate had negative and positivecontrols consisting of anti-gp46 monoclonal antibody 1C11 or controlP3×63 ascites fluid each diluted 1/50. Titers were determined as thegreatest dilution still giving twice the background cpm binding.

DETAILED DESCRIPTION OF THE INVENTION

It is the purpose of this invention to provide immunogenic peptides foruse as vaccines to elicit T-cell immunity against HTLV-I. It is afurther purpose of the invention to provide peptides for use in primingantibody response against pathogenic proteins of the HTLV-I virus astreatment for already-infected individuals.

Peptides of the invention are also useful as diagnostic agents toevaluate patient T-cell responses. The particular peptides taught hereinmay be conjugated to each other or to other moieties to specificallygenerate desired responses in the patient. Examples of such moieties areB cell epitopes to produce neutralizing antibodies and cytotoxic T-cellepitopes to induce cytotoxic T-cells.

The information relating to sequences disclosed indicates thatindividual mouse phenotypes respond with varying specificity todifferent immunogens in the same manner that individual human responsevaries. However, it is known that peptide epitopes which elicit T-cellresponses in mice also elicit immune responses in humans. (Seereferences 9-16 in the list of references.) As in mice, differentphenotypes may vary somewhat in response to a given epitope. Therefore,preferred vaccines contain more than one immunogenic dominant epitope.

Two independent series of HTLV-I envelope peptides were synthesised intwo laboratories, based on two different strategies. One set was chosenbased on prediction of amphipathic helical conformation to look forT-cell epitopes, and the other set was made originally to search forB-cell epitopes, and so had been chosen on the basis of hydrophilicityof amino acid sequence. The antigenicity of these peptides was tested onnative HTLV-I envelope protein-immunized murine lymph node cells andstrong antigenicity was predominantly detected in peptides predicted tobe amphipathic, α-helical sites. Furthermore, three antigenic peptidescould be used to immunize mice to elicit T-cells proliferating inresponse to the native envelope protein, and to prime helper T cells foran enhanced antibody response to the native envelope protein. Theseantigenic and/or immunogenic peptides identified in the murine systemshould be helpful for analysing the difference in immune responses toHTLV-I among patients with TSP/HAM and ATLL and their healthyseropositive relatives and also maybe useful for developing a peptidevaccine protecting against HTLV-I transmission and HTLV-I-associateddisease development.

The computer algorithm, AMPHI, was used for identifying predicted T-cellsites, based on segments with potential amphipathic helical structure,in the HTLV-I-envelope protein whose primary amino acid sequence wasidentified by Seiki et al. [28]. The algorithm identified 15 predictedsites; nine of them were amphipathic α-helical sites and 5 of them were3₁₀ -helical sites as shown in FIG. 1A. In one predicted site, 387-411,α-helicity changes to 3₁₀ -helical character in the C-terminal half. Oneseries of peptides, V1E1-5 and V1E7-9, were synthesized, based on theanalysis, and V1E10 was synthesized as a control peptide withnon-predicted sequence (FIG. 1B). Although another series of peptides,SP1-6 and SP8-11, were synthesized independent of these predictions, 7of 10 peptides (SP1, SP2, SP4a, SP5, SP8, SP9, and SP10) corresponded toeither α or 3₁₀ predicted sites coincidentally. Furthermore, completesharing or partial overlap of amino acid sequence was observed betweensome of the peptides in the two series: SP4a (190-209) and V1E9(268-286) included V1E8 (191-209) and SP5 (269-280), respectively andV1E7 and SP2, V1E4 and SP8, and V1E5 and SP10 overlapped partially (FIG.1B, 1C, and Table 1).

Identification of sites after immunization with native HTLV-I envelopeprotein. Table 2 shows the proliferative response of HTLV-I envelopeprotein-immune lymph node cells to the synthetic peptides. Congenic micerepresenting four independent MHC types were studied. Moreover, thesestrains differ only in their MHC region. Peptides V1E8 and SP4a inducedprominant proliferative responses of B10.BR and B10.A(5R) lymph nodecells and V1E1 elicited remarkable response only in B10.BR mice. Thesetwo sites, V1E8/SP4a and V1E1, were potent antigenic sites in HTLV-Ienvelope protein and elicited proliferative response in these strains ofmice even at 0.01 μM of antigen concentration (FIG. 2.). V1E2 and V1E9were also antigenic in envelope-immune B10.BR mice and V1E10 inB10.A(5R) mice (Table 2), but these were much less potent on a molarbasis in dose-response curves (FIG. 2). No site was identified forB10.D2 and B10.HTT (and B10.S(9R)) mice that was as highly antigenic asV1E1 and V1E8/SP4a for B10.BR and B10.A(5R) mice. However, SP1, SP5,SP10, V1E5, and V1E9 were immunodominant for B10.HTT and SP1, SP2, SP4a,SP5, V1E4, V1E7, V1E9, and V1E10 were for B10.D2 as shown in Table 2.The responses of B10.S(9R) mice were the same as those of B10.HTT (damnot shown). The fact that SP4a, but not V1E8 which is contained withinSP4a, stimulated B10.D2 envelope-immune T cells suggests that thedeterminant seen by H-2^(d) mice is slightly different from that seen bythe other strains that respond to both peptides, and requires theadditional NH₂ -terminal leucine residue present in SP4a but not inV1E8. Interestingly, all of these antigenic sites, except for V1E10,were amphipathic α-helical portions of the HTLV-I envelope and noamphipathic 3₁₀ -helical site was involved, as summarised in Table 3.

Responses to native envelope after immunization with peptides. Fordeveloping a peptide-vaccine, the candidate peptide should have thecapability to elicit in vivo a T cell response to the whole nativemolecule from which the peptide derives. The peptides, V1E1,V1E8, andV1E10, were found to be immunodominant sites by the results of the aboveexperiments in which the native envelope protein was used as immunogenand synthetic peptides were used as antigens in secondary in vitroculture (a native immunogen/peptide test antigen or "NP" experiment).Therefore B10.BR, B10.D2, and B10.A(5R) mice were immunized with thesethree peptides individually and tested the response of peptide-immunelymph node cells to the native envelope protein (a peptideimmunogen/native test antigen or "PN" experiment). As shown in FIG. 3,the peptide V1E8, antigenic in B10.BR and B10.A(5R) in the NP direction,could immunize mice to elicit the response of lymph node cells to thenative envelope protein as well as the immunogen (V1E8) itself in thesame strains of mice. Likewise, the peptides V1E1 and V1E10, antigenicin B10.BR and B10.D2, respectively, in the NP experiments, were alsoimmunogenic in the corresponding strains of mice for eliciting T cellsresponding to the native protein in PN experiments (FIG. 3). Theconcentrations of the secondary antigens producing the maximum responsesin these PN experiments were similar for the peptide immunogens and thenative protein antigen, the HTLV-I envelope protein.

Ability of peptides to prime helper T cells for antibody responses tothe whole envelope protein. In order to assess whether the peptides thatcould prime mice for a T-cell proliferative response to the nativeprotein could also prime helper T cells for an enhanced antibodyresponse to the whole envelope protein, four groups of five mice each oftwo strains were immunized first i.p. with 10 nmoles of one of threepeptides (without any carrier) or PBS as a control in CFA. Fifteen dayslater, the mice were boosted i.p. with a suboptimal dose of 5.6 μg ofaffinity-purified envelope protein in IFA, and bled on days 14 and 21after the boost. Antibodies were measured to the affinity-purifiedenvelope protein by radiobinding assay as described in Materials andMethods. Mice preimmunized with only PBS uniformly failed to produce anymeasurable binding activity (FIG. 4), consistent with the suboptimalimmunization with whole protein. In B10.BR mice, preimmunization withpeptide V1E8 and to a lesser extent with peptide V1E1, both of which areimmunogenic in this strain, produced significant titers of antibodiesbinding the envelope protein. In contrast, preimmunization with peptideV1E10 failed to enhance the antibody response in B10.BR mice which alsodo not manifest a proliferative response to this peptide. In B10.A(5R)mice, which give a proliferative response to peptides V1E8 and V1E10 butnot V1E1, an enhanced antibody response to the envelope protein wasobserved in those mice immunized with V1E8 and V1E10, and a weakerresponse on day 14 but not day 21 in those immunized with V1E1. Thus,the enhancement of antibody responses followed the same genetic Ir genecontrol as the T-cell proliferative response. Therefore, these data wereintrerprted as reflecting the priming of helper T cells so that asecondary response occurs when the mice are first immunized with wholeprotein. We noted the presence of some anti-HTLV-I envelope antibodiesin the mice immunized with peptides two weeks earlier, but before theywere boosted with whole protein (data not shown). No antibodies werefound in PBS-immune mice. This result suggests that the peptides mayalso contain B-cell epitopes. In particular, peptide SP4a, whichcoincides with V1E8, has been shown to be a B-cell epitope in humans(Palker et. al. J. Immunol. 142:971-978). However, even if some primingof B cells occurs, such priming of B cells by uncoupled small peptideswithout a carrier implies that these peptides contain effective helperT-cell determinants. Thus, in any case, the results of immunization withuncoupled peptide and the Ir gene control of the antibody responseparallel to that of the T-cell proliferative response indicate that thethree peptides tested can induce T-cell help as well as T-cellproliferation.

The overlap of amino acid sequences useful as immunogens and as antiodyprimors has been observed in several cases, possibly due to therelatively high hydrophilic character of some amphipathic helicalsegments. However, as disclosed herein, hydrophilicity of amino acidsequence of peptides is not significantly correlated with theimmunodominance of peptides for proliferative T-cell responses (J. L.Spouge, H. R. Guy, and J. A. Berzofsky, unpublished observations). Infact, one of the two most potent immunodominant sites, V1E1 in gp21, wasnot identified by the algorithm that selected peptide sequences becauseof their high hydrophilicity. Hence, the Preneficial peptides are notobvious in view of prior trackings in the art.

Table 3A shows the relation between immunodominance and the potentialamphipathicity of the HTLV-I envelope peptides. Interestingly, ten ofthe eleven immunodominant sites (all except for V1E10) were amphipathicα-helical sites and no amphipathic 3₁₀ -helical sites were identified asimmunodominant. Only one of four non-helical sites were immunodominant.The conformation of 3₁₀ -helices is energetically less stable than thatof α-helices and usually short pieces of 3₁₀ -helix tend to be at the N-and C-termini of α-helices. Although the original study (Margalit el.al. J. Immunol. 138:2213-2229) of published immunodominant sites did notdetect a difference in antigenicity between amphipathic α-helices and3₁₀ -helices, P. Hale et al.(manuscript submitted) recently found thatamphipathic 3₁₀ -helical sites in the HIV envelope protein were rarelyimmunogenic as compared to the high tendency toward immunodominance ofthe amphipathic α-helical sites. It is noteworthy that the difference inantigenicity between amphipathic α-helices and 3₁₀ -helices is revealedin the envelope protein of two human retroviruses. The efficacy of theprediction of amphipathic α-helical segments as immunodominant sites inHTLV-I envelope protein is demonstrated in Table 3B. Of 11 sites foundto be immunogenic, 10 sites were segments predicted to be amphipathicα-helices. Furthermore, no site predicted to be an amphipathic α-helicalsite is among the 6 sites found to be non-immunogenic.

The proliferative responses of native envelope protein-immunized lymphnode cells to the synthetic peptides were clearly dependent on the MHChaplotype. Four congenic strains of mice were used, differing only intheir MHC type. They represent eight different I-A and I-E class II MHCmolecules. Sites 190-209 (V1E8/SP4a) and 342-363 (V1E1) were found to beespecially potent sites in the HTLV-I envelope protein: the responses ofB10.BR and B10.A(5R) mice to V1E8/SP4a and of B10.BR mice to V1E1occurred even at the low concentration of 0.01 μM in NP experiments.Although the maximum response of envelope protein-immune lymph nodecells was not different among the four congenic strains of mice, B10.BR,B10.D2, B10.A(5R), and B10.HTT, no site was identified to be so potentat low concentrations for B10.D2 and B10.HTT mice as V1E1 and V1E8/SP4awere for B10.BR and B10.A(5R) mice. It was also found that three of theepitope peptides of the HTLV-I envelope (V1E8/SP4A, V1E1, and V1E10)primed mice for memory T cell help to enhance antibody responses toB-cell epitopes of the envelope protein.

Asymptomatic seropositive carriers of HTLV-I and patients with ATLL andTSP/HAM have comparable anti-HTLV-I antibody titers in their sera. Incontrast, a difference in HLA haplotype and in lymphocyte proliferativeresponse to HTLV-I virions among the patients with these two distinctdiseases was reported from southwestern Japan, an endemic area forHTLV-I (Usuku et. al. Ann. Neurol 23:S143-S150). The patients with HAMwere high responders to HTLV-I virions in peripheral blood lymphocyte(PBL) cultures in vitro, whereas ATLL patients were low responders intheir analysis. Moreover, this difference in lymphocyte response wascorrelated to the difference in HLA haplotype: healthy HTLV-I carrierswith HAM-associated HLA haplotypes tended to show higher HTLV-I-specificlymphocyte responses than healthy carriers with HLA haplotypescorrelated with development of ATLL. When the response of human PBL tothe synthetic HTLV-I peptides identified in the current study isanalysed, it should be possible to detect more distinct MHC-associateddifferences in the T-cell responses among the carriers and patients withATLL and HAM because individual peptide epitopes should show clearergenetic restriction than the whole envelope protein, as shown here inmice. Also, responses to particular peptides may be associated with thediseases TSP/HAM, especially if these diseases have autoimmunemechanisms.

Recently, Palker et al. (J.Immunol. 142:971-978) reported that thecentral region of HTLV-I gp46 envelope glycoprotein defined by syntheticpeptide SP4A (residues 190-209) bound antibodies from 78% of HTLV-Iseropositive humans. Thus, the SP4A/V1E8 region contains animmunodominant T-cell site in mice of three of four MHC types tested(current study) and also a major B-cell epitope in man. While sites of Band T cell recognition frequently differ in location within a proteinand in structural and sequence features (Berzofsky et. al. Immunol. Rev.98:9-52), major T- and B-cell sites can coincide within the samemolecule (Takahashi et. al. Proc. Natl. Acad. Sci. USA 85:3105-3109.,Thomas et.al. Eur. J. Immunol. 17:133-136., Palker et.al. J. Immunol.142:in press).

As the incidence of disease among HTLV-I infection is low compared withAIDS virus infection, it is difficult to test a vaccine for HTLV-I evenif it is developed. However, this observation also suggests that inHTLV-I infection, the immune system is working more effectively forprotection against the development of the diseases than in AIDS virusinfection.

                                      TABLE 1                                     __________________________________________________________________________    Sequence of synthetic HTLV1 envelope peptides                                               NUMBER OF                                                       PEPTIDES      AMINO ACIDS                                                                            AMINO ACID SEQUENCE.sup.a                              __________________________________________________________________________    SP1 (SEQ. ID. NO.: 1)                                                                       33-47    VSSYHSKPCNPAQPV                                        SP2 (SEQ. ID. NO.: 2)                                                                        86-107  (C)PHWTKKPNRNGGGYYSASYSDP                              SP3 (SEQ. ID. NO.: 3)                                                                       176-189  (C)LNTEPSQLPPTAPP(Y)                                   SP4a (SEQ. ID. NO.: 4)                                                                      190-209  (C)LLPHSNLDHILEPSIPWKSK(Y)                             SP5 (SEQ. ID. NO.: 5)                                                                       269-280  (Y)LPFNWTHCFDPQ(C)                                     SP6 (SEQ. ID. NO.: 6)                                                                       296-312  (C)PPFSLSPVPTLGSRSRR                                   SP8 (SEQ. ID. NO.: 7)                                                                       400-415  CRFPNITITNSHVPILQE                                     SP9 (SEQ. ID. NO.: 8)                                                                       411-422  (C)PILQERPPLENR                                        SP10 (SEQ. ID. NO.: 9)                                                                      462-480  CILRQLRHLPSRVRYPHYS                                    SP11 (SEQ. ID. NO.: 10)                                                                     475-488  (C)RYPHYSLIKPESSL                                      V1E1 (SEQ. ID. NO.: 11)                                                                     342-363  SGKSLLHEVDKDISQLTQAIVK                                 V1E2 (SEQ. ID. NO.: 12)                                                                     353-370  DISQLTQAIVKNHKNLLK                                     V1E3 (SEQ. ID. NO.: 13)                                                                     362-378  VKNHKNLLKIAQYAAQN                                      V1E4 (SEQ. ID. NO.: 14)                                                                     388-402  EQGGLCKALQEQCRF                                        V1E5 (SEQ. ID. NO.: 15)                                                                     458-475  LAGPCILRQLRHLPSRVR                                     V1E7 (SEQ. ID. NO.: 16)                                                                      97-111  GGYYSASYSDPCSLK                                        V1E8 (SEQ. ID. NO.: 17)                                                                     191-209  LPHSNLDHILEPSIPWKSK                                    V1E9 (SEQ. ID. NO.: 18)                                                                     268-286  TLPFNWTHCFDPQIQAIVS                                    V1E10 (SEQ. ID. NO.: 19)                                                                    141-156  FTQEVSRLNINLHFSK                                       __________________________________________________________________________     .sup.a Amino acids in parentheses have been added to peptides to              facilitate coupling to carrier protein (C) and iodination of peptide (Y)      for another study [24]. These residues in parentheses are not present in      the predicted amino acid sequence of HTLVI envelope glycoprotein reported     by Seiki et al.[28].                                                     

                                      TABLE 2                                     __________________________________________________________________________    The proliferative response of HTLV1 envelope protein-immunized lymph node     cells                                                                         to the synthetic peptides and the immunogen                                   B10.BR           B10.D2     B10.A(5R)  B10.HTT                                Antigens                                                                            ACPM (SEM)                                                                            S.I.                                                                             ΔCPM (SEM)                                                                      S.I.                                                                             ΔCPM (SEM)                                                                      S.I.                                                                             ΔCPM (SEM)                                                                      S.I.                           __________________________________________________________________________    SP1   -2,792 (1.05)                                                                         0.57                                                                             16,121 (1.19)                                                                         2.99                                                                             -1,886 (1.34)                                                                         0.52                                                                             11,919 (1.22)                                                                         5.15                           SP2   686 (1.13)                                                                            1.11                                                                             23,724 (1.21)                                                                         3.93                                                                             -106 (1.37)                                                                           0.97                                                                             *5,008 (1.18)                                                                         2.74                           SP3   359 (1.14)                                                                            1.06                                                                             *11,148 (1.32)                                                                        2.38                                                                             -1,405 (1.08)                                                                         0.64                                                                             2,733 (1.13)                                                                          1.95                           SP4a  26,184 (1.16)                                                                         5.04                                                                             17,561 (1,18)                                                                         3.17                                                                             34,607 (1.08)                                                                         7.50                                                                             867 (1.29)                                                                            1.30                           SP5   -1,159 (1.03)                                                                         0.82                                                                             28,985 (1,18)                                                                         4.58                                                                             552 (1.12)                                                                            1.14                                                                             6,433 (1.24)                                                                          3.24                           SP6   544 (1.36)                                                                            1.08                                                                             3,313 (1.22)                                                                          1.41                                                                             2,037 (1.04)                                                                          1.51                                                                             2,069 (1.21)                                                                          1.72                           SP8   -948 (1.25)                                                                           0.85                                                                             4,890 (1.49)                                                                          1.60                                                                             2,601 (1.07)                                                                          1.66                                                                             2,145 (1.21)                                                                          1.70                           SP9   3,240 (1.17)                                                                          1.50                                                                             4,074 (1.30)                                                                          1.46                                                                             1,990 (1.10)                                                                          0.91                                                                             2,279 (1.18)                                                                          1.74                           SP10  2,218 (1.10)                                                                          1.34                                                                             *14,813 (1.44)                                                                        2.83                                                                             -79 (1.14)                                                                            0.98                                                                             12,173 (1.05)                                                                         4.96                           SP11  3,946 (1.20)                                                                          1.61                                                                             *11,811 (1.30)                                                                        2.46                                                                             -367 (1.20)                                                                           0.91                                                                             3,343 (1.18)                                                                          2.09                           V1E1  30,621 (1.11)                                                                         5.73                                                                             957 (1.41)                                                                            1.12                                                                             -194 (1.17)                                                                           0.95                                                                             862 (1.13)                                                                            1.28                           V1E2  21,191 (1.27)                                                                         4.27                                                                             1,252 (1.17)                                                                          1.15                                                                             104 (1.20)                                                                            1.03                                                                             2,155 (1.29)                                                                          1.70                           V1E3  7,444 (1.09)                                                                          2.15                                                                             1,910 (1.21)                                                                          1.22                                                                             -2,440 (1.11)                                                                         0.38                                                                             792 (1.27)                                                                            1.26                           V1E4  1,289 (1.07)                                                                          1.20                                                                             25,568 (1.06)                                                                         3.97                                                                             -1,862 (1.13)                                                                         0.53                                                                             1,111 (1.19)                                                                          1.37                           V1E5  2,498 (1.16)                                                                          1.39                                                                             7,186 (1.46)                                                                          1.84                                                                             -1,990 (1.30)                                                                         0.50                                                                             4,669 (1,48)                                                                          2.55                           V1E7  -1,072 (1.16)                                                                         0.83                                                                             13,155 (1.08)                                                                         2.53                                                                             -221 (1.39)                                                                           0.94                                                                             2,885 (1.06)                                                                          1.95                           V1E8  26,747 (1.11)                                                                         5.13                                                                             -2,009 (1.12)                                                                         0.77                                                                             25,993 (1.07)                                                                         7.56                                                                             1,928 (1.22)                                                                          1.64                           V1E9  19,605 (1.28)                                                                         3.76                                                                             26,721 (1.10)                                                                         4.11                                                                             8.005 (1.39)                                                                          2.31                                                                             8,196 (1.25)                                                                          3.71                           V1E10 7,438 (1.07)                                                                          1.43                                                                             27,183 (1.26)                                                                         4.16                                                                             20,477 (1.20)                                                                         5.92                                                                             1,149 (1.20)                                                                          1.38                           Env. prot.                                                                          106,677 (1.16)                                                                        17.5                                                                             108,617 (1.10)                                                                        13.6                                                                             91,367 (1.04)                                                                         24.1                                                                             48,222 (1.10)                                                                         17.0                           __________________________________________________________________________

DISCUSSION OF TABLE 2

a. The native envelope protein-immune lymph node cells were culturedwith three different concentrations of peptides: 0.3 μM, 1.0 μM, and 3.0μM. The [³ H]-TdR incorporation into the responding cells at highestconcentration of the antigens (3 μM) is shown as Δ geometric mean (cpm),SEM, and stimulation indices (S.I.) (ratio of experimental mean tocontrol mean without antigen).

b. The values underlined were highly statistically significant (p<0.01).Also tthese peptides stimulated significantly at lower antigenconcentrations. These peptides were identified to be immunodominant forthe corresponding mouse strains. The values with asterisks werestatistically significant (0.01<p<0.05) only at the highest antigenconcentration, 3.0 μM.

                  TABLE 3                                                         ______________________________________                                        Correlation of experimental immunodominance with                              α-helical amphipathicity prediction                                     ______________________________________                                        A.                                                                                          Type predicted                                                                  α-helix                                                                         3.sub.10 helix                                                                           non-helical                                ______________________________________                                        Tested sites    10      3          4                                          Immunodominant sites                                                                          10      0          1                                          %               100     0          25                                         ______________________________________                                        B.                                                                                             Found      Found non-                                                         immunogenic                                                                              immunogenic                                       ______________________________________                                        Total sites      11         6                                                 Predicted to be  10         0                                                 amphipathic alpha helix                                                       ______________________________________                                    

The peptides of the invention may be administered as immunogens in theusual carriers. The compositions for use as immunogens may containadjuvants such as alum. Compositions containing VIE1, VIE8/SP4a andVIE10 are preferred. However, it is advisable that more than one of theepitopes taught herein be given. Compositions containing at least threeepitopes are preferred.

Compositions may be administered in the usual manner. However, preferredroutes of administration for vaccine use are subcutaneous, intradermal,or intramuscular routes.

The compositions of the invention can also be used as primers to elicitT-cell responses.

References

1. Poiesz, B. J., F. W. Ruscetti, A. F. Gazdar, P. A. Bunn, J. D. Minna,and R. C. Gallo. 1980. Detection and isolation of type C retrovirusparticles from fresh and cultured lymphocytes of a patient withcutaneous T-cell lymphoma. Proc. Natl. Acad. Sci. U.S.A. 77:7415-7419.

2. Yoshida, M., I. Miyoshi, and Y. Hinuma. 1982. Isolation andcharacterization of retrovirus from cell lines of human adult T-cellleukemia and its implication in the disease. Proc.Natl.Acad.Sci.USA79:2031-2035.

3. Johnson, R. T., and J. C. McArthur. 1987. Myelopathies and RetroviralInfections. Ann.Neurol 21:113-116.

4. Gessain, A., J. C. Vernant, L. Maurs, F. Barin, O. Gout, A. Calender,and G. De-The. 1985. Antibodies to Human T-Lymphotropic virus Type-I inPatients with Tropical Spastic Paraparesis. Lancet 2:407-410.

5. Rodgers-Johnson, P., D. C. Gajdusek, O. St. C. Morgan, V. Zaninovic,P. S. Sarin, and D. S. Graham. 1985. HTLV-I and HTLV-III Antibodies andTropical Spastic Paraparesis. Lancet 2:1247-1248.

6. Vernant, J. C., L. Maurs, A. Gessain, F. Barin, O. Gout, J. M.Delaporte, K. Sanhadji, G. Buisson, and G. De-The. 1987. EndemicTropical Spastic Paraparesis Associated with Human T-Lymphotropic VirusType I: A Clinical and Seroepidemiological Study of 25 Cases. Ann.Neurol21:123-130.

7. Osame. M., K. Usuku, S. Izumo, N. Ijichi, H. Amitani, A. Igata, M.Matsumoto, and M. Tara. 1986. HTLV-I associated myelopathy, a newclinical entity. Lancet 1:1031-1032.

8. Usuku, K., S. Sonoda, M. Osame, S. Yashiki, K. Takahashi, M.Matsumoto, T. Sawada, K. Tsuji, M. Tara, and A. Igata. 1988. HLAhaplotype-linked high immune responsiveness against HTLV-I inHTLV-I-associated myelopathy: comparison with adult T-cellleukemia/lymphoma. Ann.Neurol 23:S143-S150.

9. Lamb, J. R., D. D. Eckels, P. Lake, J. N. Woody, and N. Green. 1982.Human T cell clones recognize chemically synthesized peptides ofinfluenza hemagglutinin. Nature 300:66-69.

10. Hurwitz, J. L., E. Heber-Katz, C. J. Hackett, and W. J. Gerhard.1984. Characterization of the murine TH response to influenza virushemagglutinin: evidence for three major specificities. J.Immunol.133:3371-3377.

11. Cease, K. B., H. Margalit, J. L. Cornette, S. D. Putney, W. G.Robey, C. Ouyang, H. Z. Streicher, P. J. Fischinger, R. C. Gallo, C.Delisi, and J. A. Berzofsky. 1987. Helper T cell antigenic siteidentification in the AIDS virus gp 120 envelope protein and inductionof immunity in mice to the native protein using a 16-residue syntheticpeptide. Proc. Natl. Acad. Sci. USA 84:4249-4253.

12. Berzofsky, J. A., A. Bensussan, K. B. Cease, J. F. Bourge, R.Cheynier, Z. Lurhuma, J.-J. Salaun, R. C. Gallo, G. M. Shearer, and D.Zagury. 1988. Antigenic peptides recognized by T lymphocytes from AIDSviral envelope-immune humans. Nature 334:706-708.

13. Good, M. F., W. L. Maloy, M. N. Lunde, H. Margalit, J. L. Cornette,G. L. Smith, B. Moss, L. H. Miller, and J. A. Berzofsky. 1987.Construction of a synthetic immunogen: use of a new T-helper epitope onmalaria circumsporozoite protein. Science 235:1059-1062.

14. Good, M. F., D. Pombo, I. A. Quakyi, E. M. Riley, R. A. Houghten, A.Menon, D. W. Alling, J. A. Berzofsky, and L. H. Miller. 1988. Human Tcell recognition of the cicumsporozoite protein of Plasmodiumfalciparum. Immunodominant T cell domains map to the polymorphic regionsof the molecule. Proc. Natl. Acad. Sci. USA 85:1199-1203.

15. Dontfraid, F., M. A. Cochran, D. Pombo, J. D. Knell, I. Quakyi, S.Kumar, R. A. Houghten, J. A. Berzofsky, L. H. Miller, and M. F. Good.1988. Human and murine CD4 T-cell epitopes map to the same region of themalaria circumsporozoite protein: Limited immunogenicity of sporozoitesand cirumsporozoite protein. Mol. Biol. Med.

16. Sinigaglia, F., M. Guttinger, J. Kilgus, D. M. Doran, H. Matile, H.Etlinger, A. Trzeciak, D. Gillessen, and J. R. L. Pink. 1988. A malariaT-cell epitope recognized in association with most mouse and human MHCclass II molecules. Nature 336:778-780.

17. Delisi, C., and J. A. Berzofsky. 1985. T cell antigenic sites tendto be amphipathic structures. Proc. Natl. Acad. Sci. U.S.A.82:7048-7052.

18. Margalit, H., J. L. Spouge, J. L. Cornette, K. Cease, C. Delisi, andJ. A. Berzofsky. 1987. Prediction of immunodominant helper T-cellantigenic sites from the primary sequence. J. Immunol. 138:2213-2229.

19. Palker, T. J., M. E. Clark, M. G. Sarngadharan, and T. J. Matthews.1987. Purification of envelope glycoproteins of human T celllymphotropic virus type I (HTLV-I) by affinity chromatography. J. Virol.Methods 18:243.

20. Spouge, J. L., H. R. Guy, J. L. Cornette, H. Margalit, K. Cease, J.A. Berzofsky, and C. Delisi. 1987. Strong conformational propensitiesenhance T-cell antigenicity. J. Immunol. 138:204-212.

21. Berzofsky, J. A., K. B. Cease, J. L. Cornette, J. L. Spouge, H.Margalit, I. J. Berkower, M. F. Good, L. H. Miller, and C. Delisi. 1987.Protein antigenic structures recognized by T cells: Potentialapplications to vaccine design. Immunol. Rev. 98:9-52.

22. Cornette, J. L., H. Margalit, C. Delisi, and J. A. Berzofsky. 1989.Concepts and methods in the identification of T cell epitopes and theiruse in the construction of synthetic vaccines. Methods in Enzymol.

23. Kyte, J., and R. F. Doolittle. 1982. A simple method for displayingthe hydrophilic character of a protein. J.Mol.Biol. 157:105.

24. Palker, T. J., M. E. Tanner, R. M. Scearce, R. D. Streilein, M. E.Clark, and B. F. Haynes. 1989. Mapping of immunogenic regions of human Tcell leukemia virus type I (HTLV-I) gp46 and gp 21 envelopeglycoproteins with env-encoded synthetic peptides and a monoclonalantibody to gp46. J. Immunol. 142:971-978.

25. Merrifield, R. B. 1965. Automated synthesis of peptides. Science150:178-185.

26. Stewart, J. M., and J. D. Young. 1984. Solid Phase PeptideSynthesis. Pierce Chemical Company, Rockford, Ill.,

27. Corradin, G., H. M. Etlinger, and J. M. Chiller. 1977. Lymphocytespecificity in protein antigens. I. Characterization of theantigen-induced in vitro T cell-dependent proliferative response withlymph node cells from primed mice. J. Immunol. 119:1048.

28. Seiki, M., S. Hattori, and M. Yoshida. 1982. Human adult T-cellleukemia virus: Molecular cloning of the provirus DNA and the uniqueterminal structure. Proc.Natl.Acad.Sci.USA 79:6899-6902.

29. Takahashi, H., J. Cohen, A. Hosmalin, K. B. Cease, R. Houghten, J.Cornette, C. Delisi, B. Moss, R. N. Germain, and J. A. Berzofsky. 1988.An immunodominant epitope of the HIV gp 160 envelope glycoproteinrecognized by class I MHC molecule-restricted murine cytotoxic Tlymphocytes. Proc. Natl. Acad. Sci. USA 85:3105-3109.

30. Thomas, D. B., J. J. Skehel, K. H. G. Mills, and C. M. Graham. 1987.A single amino acid substitution in influenza haemagglutinin abrogatesrecognition by a monoclonal antibody and a spectrum of subtype-specificL3T4+ T cell clones. Eur.J.Immunol. 17:133-136.

31. Palker, T. J., T. J. Matthews, A. Langlois, M. E. Tanner, M. E.Martin, R. M. Scearce, J. E. Kim, J. A. Berzofsky, D. P. Bolognesi, andB. F. Haynes. 1989. Polyvalent human immunodeficiency virus syntheticimmunogen comprised of envelope gp120 T helper cell sites and B cellneutralization epitopes. J.Immunol. 142: in press.

32. Malik, K. T. A., J. Evan, and A. Karpas. 1988. Molecular cloning andcomplete nucleotide sequence of an adult T cell leukaemia virus/human Tcell leukaemia virus type I (ATLV/HTLV-I) isolate of Caribbean origin:relationship to other members of the ATLV/HTLV-I subgroup. J. Gen.Virol. 69:1695.

    __________________________________________________________________________    SEQUENCE LISTING                                                              (1) GENERAL INFORMATION:                                                      (iii) NUMBER OF SEQUENCES: 19                                                 (2) INFORMATION FOR SEQ ID NO:1:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 15 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS:                                                             (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..15                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- SP1                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:                                       ValSerSerTyrHisSerLysProCysAsnProAlaGlnProVal                                 151015                                                                        (2) INFORMATION FOR SEQ ID NO:2:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 23 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..23                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp2                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:                                       CysProHisTrpThrLysLysProAsnArgAsnGlyGlyGlyTyrTyr                              151015                                                                        SerAlaSerTyrSerAspPro                                                         20                                                                            (2) INFORMATION FOR SEQ ID NO:3:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 16 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..16                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp3                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:                                       CysLeuAsnThrGluProSerGlnLeuProProThrAlaProProTyr                              151015                                                                        (2) INFORMATION FOR SEQ ID NO:4:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 22 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..22                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp4a                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:                                       CysLeuLeuProHisSerAsnLeuAspHisIleLeuGluProSerIle                              151015                                                                        ProTrpLysSerLysTyr                                                            20                                                                            (2) INFORMATION FOR SEQ ID NO:5:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 14 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..14                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp5                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:                                       TyrLeuProPheAsnTrpThrHisCysPheAspProGlnCys                                    1510                                                                          (2) INFORMATION FOR SEQ ID NO:6:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 18 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..18                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp6                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:                                       CysProProPheSerLeuSerProValProThrLeuGlySerArgSer                              151015                                                                        ArgArg                                                                        (2) INFORMATION FOR SEQ ID NO:7:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 16 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..16                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp8                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:                                       CysArgPheProAsnIleThrAsnSerHisValProIleLeuGlnGlu                              151015                                                                        (2) INFORMATION FOR SEQ ID NO:8:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 13 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..13                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp9                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:                                       CysProIleLeuGlnGluArgProProLeuGluAsnArg                                       1510                                                                          (2) INFORMATION FOR SEQ ID NO:9:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 19 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..19                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp10                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:                                       CysIleLeuArgGlnLeuArgHisLeuProSerArgValArgTyrPro                              151015                                                                        HisTyrSer                                                                     (2) INFORMATION FOR SEQ ID NO:10:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 15 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..15                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- sp11                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:                                      CysArgTyrProHisTyrSerLeuIleLysProGluSerSerLeu                                 151015                                                                        (2) INFORMATION FOR SEQ ID NO:11:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 22 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..22                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- v1e1                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:                                      SerGlyLysSerLeuLeuHisGluValAspLysAspIleSerGlnLeu                              151015                                                                        ThrGlnAlaIleValLys                                                            20                                                                            (2) INFORMATION FOR SEQ ID NO:12:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 18 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..18                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- v1e2                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:                                      AspIleSerGlnLeuThrGlnAlaIleValLysAsnHisLysAsnLeu                              151015                                                                        LeuLys                                                                        (2) INFORMATION FOR SEQ ID NO:13:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 17 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..17                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- v1e3                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:                                      ValLysAsnHisLysAsnLeuLeuLysIleAlaGlnTyrAlaAlaGln                              151015                                                                        Asn                                                                           (2) INFORMATION FOR SEQ ID NO:14:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 15 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..15                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- v1e4                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:                                      GluGlnGlyGlyLeuCysLysAlaLeuGlnGluGlnCysArgPhe                                 151015                                                                        (2) INFORMATION FOR SEQ ID NO:15:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 18 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..18                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- v1e5                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:15:                                      LeuAlaGlyProCysIleLeuArgGlnLeuArgHisLeuProSerArg                              151015                                                                        ValArg                                                                        (2) INFORMATION FOR SEQ ID NO:16:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 15 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..15                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- v1e7                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:16:                                      GlyGlyTyrTyrSerAlaSerTyrSerAspProCysSerLeuLys                                 151015                                                                        (2) INFORMATION FOR SEQ ID NO:17:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 19 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..19                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- v1e8                            (xi) SEQUENCE DESCRIPTION: SEQ ID NO:17:                                      LeuProHisSerAsnLeuAspHisIleLeuGluProSerIleProTrp                              151015                                                                        LysSerLys                                                                     (2) INFORMATION FOR SEQ ID NO:18:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 19 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..19                                                           (D) OTHER INFORMATION: /label= peptid.sub.-- v1e9                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:18:                                      ThrLeuProPheAsnTrpThrHisCysPheAspProGlnIleGlnAla                              151015                                                                        IleValSer                                                                     (2) INFORMATION FOR SEQ ID NO:19:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 16 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: Not Relevant                                                (D) TOPOLOGY: Not Relevant                                                    (ii) MOLECULE TYPE: peptide                                                   (iii) HYPOTHETICAL: NO                                                        (v) FRAGMENT TYPE: internal                                                   (vi) ORIGINAL SOURCE:                                                         (A) ORGANISM: htlv-I                                                          (ix) FEATURE:                                                                 (A) NAME/KEY: Peptide                                                         (B) LOCATION: 1..16                                                           (D) OTHER INFORMATION: /label= peptide.sub.-- v1e10                           (xi) SEQUENCE DESCRIPTION: SEQ ID NO:19:                                      PheThrGlnGluValSerArgLeuAsnIleAsnLeuHisPheSerLys                              151015                                                                        __________________________________________________________________________

We claim:
 1. A method of priming a T-cell response in a subject byadministration of a composition comprising a peptide having an aminoacid sequence selected from the group consisting ofSGKSLLHEVDKDISQLTQAIVK (SEQ. ID. NO.:11), DISQLTQAIVKNHKNLLK (SEQ. ID.NO.:12), VKNHKNLLKIAQYAAQN (SEQ. ID. NO.:13), EQGGLCKALQEQCRF (SEQ. ID.NO.:14), LAGPCILRQLRHLPSRVR (SEQ. ID. NO.:15), GGYYSASYSDPCSLK (SEQ. ID.NO.:16), TLPFNWTHCFDPQIQAIVS (SEQ. ID. NO.:18), FTQEVSRLNINLHFSK (SEQ.ID. NO.:19) and LPHSNLDHILEPSIPWKSK (SEQ. ID. NO.:17) and apharmaceutically acceptable carrier.
 2. A method of priming a T-cellresponse in a subject by administration of a composition comprising apeptide having an amino acid sequence selected from the group consistingof EQGGLCKALQEQCRF (SEQ. ID. NO.:14), LAGPCILRQLRHLPSRVR (SEQ. ID.NO.:15), GGYYSASYSDPCSLK (SEQ. ID. NO.:16), LPHSNLDHILEPSIPWKSK (SEQ.ID. NO.:17) and TLPFNWTHCFDPQIQAIVS (SEQ. ID. NO.:18) and apharmaceutically acceptable carrier.
 3. A method of priming a T-cellresponse in a subject by administration of a composition comprising apeptide consisting of amino acids having a sequence selected from thegroup consisting of SGKSLLHEVDKDISQLTQAIVK (SEQ. ID. NO.:11),DISQLTQAIVKNHKNLLK (SEQ. ID. NO.:12), VKNHKNLLKIAQYAAQN (SEQ. ID.NO.:13), and FTQEVSRLNINLHFSK (SEQ. ID. NO.:19).
 4. A method of claim 3,wherein said peptide has an amino acid sequence FTQEVSRLNINLHFSK (SEQ.ID. NO.:19).
 5. A method of claim 3, wherein said peptide has an aminoacid sequence SGKSLLHEVDKDISQLTQAIVK (SEQ. ID. NO.:11).
 6. A method ofclaim 3, wherein said peptide has an amino acid sequenceDISQLTQAIVKNHKNLLK (SEQ. ID. NO.:12).
 7. A method of claim 3, whereinsaid peptide has an amino acid sequence VKNHKNLLKIAQYAAQN (SEQ. ID.NO.:13).